1. Field of the Invention
The instant disclosure relates to an extension case and a mobile terminal assembly using the same; more particularly, to an extension case for a mobile terminal device that incorporates an add-on battery and a radio frequency identification (RFID) antenna.
2. Description of Related Art
As wireless technology rapidly expands, a mobile terminal device (such as a cell phone) is no longer just used as a voice communication tool. Instead, the mobile terminal has been combined with other technologies to make it more diverse functions, such as Near Field Communication (NFC) technology, which developed from a radio frequency identification (RFID) technology of the wireless devices.
In 13.56 MHz frequency band, the NFC technology is able to apply the RFID technology for transmitting data in short distance at low power. When the use of the NFC technology by allowing two or more terminals to each other close, without requiring any user manipulation that is able to exchange information. Furthermore, the majority of the NFC technology is standardized by the European computer vendors alliance. Nokia, Sony, and Philips are involved in standardization and commercialization of the NFC technology.
Therefore, the NFC mobile terminal device used for payment has become an important application of the mobile terminal device. Traditional NFC antenna is set on the system circuit board of the mobile terminal device, if the NFC antenna is too close to the components of the system circuit board (or the rechargeable battery of the mobile terminal device), the system circuit board will have NFC antenna signal transceiver impact.
To address the above issues, the inventors strive via industrial experience and academic research to present the instant disclosure, which can effectively improve the limitations described above.